import { NextResponse } from "next/server"
import { eq } from "drizzle-orm"
import { db } from "@/lib/db"
import { profiles } from "@/lib/db/schema"
import { getSessionUser } from "@/lib/session"
import { paypalConfigured } from "@/lib/paypal/client"
import { getPaypalPlanId } from "@/lib/paypal/plans"
import { createSubscription, createOrder } from "@/lib/paypal/checkout"
import { PLAN_AMOUNTS } from "@/lib/stripe/plans"

const RECURRING = new Set(["pro", "landlord"])

// Start a PayPal checkout for a plan upgrade and return the approval URL.
// Recurring plans → Subscriptions API; lifetime → one-time Orders API.
export async function POST(request: Request) {
  if (!paypalConfigured()) {
    return NextResponse.json({ error: "PayPal is not configured" }, { status: 400 })
  }
  const user = await getSessionUser()
  if (!user) return NextResponse.json({ error: "Unauthorized" }, { status: 401 })

  const { plan, interval } = (await request.json().catch(() => ({}))) as {
    plan?: string
    interval?: "month" | "year"
  }
  if (!plan || (plan !== "lifetime" && !RECURRING.has(plan))) {
    return NextResponse.json({ error: "Invalid plan" }, { status: 400 })
  }

  const appUrl = process.env.NEXT_PUBLIC_APP_URL!
  const cancelUrl = `${appUrl}/settings/billing?canceled=true`

  try {
    if (plan === "lifetime") {
      const { approveUrl } = await createOrder({
        amount: PLAN_AMOUNTS.lifetime,
        userId: user.id,
        plan: "lifetime",
        returnUrl: `${appUrl}/api/paypal/return?type=order`,
        cancelUrl,
      })
      if (!approveUrl) throw new Error("PayPal did not return an approval URL")
      return NextResponse.json({ url: approveUrl })
    }

    const billingInterval = interval === "year" ? "year" : "month"
    const planId = getPaypalPlanId(plan as "pro" | "landlord", billingInterval)
    if (!planId) {
      return NextResponse.json({ error: "That plan isn't available on PayPal yet." }, { status: 400 })
    }

    const profile = await db.query.profiles.findFirst({
      where: eq(profiles.id, user.id),
      columns: { email: true },
    })

    const { approveUrl } = await createSubscription({
      planId,
      userId: user.id,
      plan,
      email: profile?.email ?? user.email,
      returnUrl: `${appUrl}/api/paypal/return?type=subscription`,
      cancelUrl,
    })
    if (!approveUrl) throw new Error("PayPal did not return an approval URL")
    return NextResponse.json({ url: approveUrl })
  } catch (e) {
    return NextResponse.json(
      { error: (e as Error).message || "PayPal checkout failed" },
      { status: 502 }
    )
  }
}